Adsorptive structures and the use thereof

ABSTRACT

The invention relates to adsorptive structures based on agglomerates of adsorber particles, each comprising a plurality of granular, preferably speherical adsorber particles, and to the production of said agglomerates, and to the use thereof. The adsorber particles of the individual agglomerates are each connected to each other by means of a preferably thermoplastic organic polymer, particularly a binder material, or the adsorber paraticles of the individual agglomerates are bonded to and/or made to adhere to a preferably thermoplastic organic polymer, particularly a hinder material.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a National Stage filing of International ApplicationPCT/EP 2009/006642, filed Sep. 14, 2009, entitled “ADSORPTIVE STRUCTURESAND THE USE THEREOF” claiming priority to German Applications DE 10 2008057 475.9, filed Nov. 14, 2008; DE 10 2008 057 509.7 filed Nov. 15,2008; and DE 10 2008 058 249.2 filed Nov. 19, 2008. The subjectapplication claims priority to PCT/EP 2009/006635, and to GermanApplications No. DE 10 2008 057 475.9; DE 10 2008 057 509.7; and DE 102008 058 249.2, and incorporates all by reference herein, in theirentirety.

BACKGROUND OF THE INVENTION

The present invention relates to the field of adsorption filtertechnology.

The present invention more particularly relates to adsorptive structuresbased on agglomerates of adsorbent particles, and to a process for theirproduction and their use.

The present invention further relates to adsorptive molded partsobtainable from the adsorptive structures of the present invention, andto a process for their production and their use.

Finally, the present invention relates to filters comprising theadsorptive structures of the present invention or the adsorptive moldedparts of the present invention.

To clean or purify fluidic media, more particularly gases, gas streamsor gas mixtures, such as air for example, or alternatively liquids, suchas water for example, particulate systems based on particles withspecific activity (e.g., adsorbents, ion exchangers, catalysts, etc) areoften used. For instance, the use of adsorbent particles to remove toxicor noxiant substances and odors from gas or air streams or else fromliquids is known from the prior art.

The use of loose beds of the aforementioned particles, particularly inthe form of loose granular-bed filters, is the central form whereby theparticles concerned, such as adsorbent particles for example, arebrought into contact with the gas or liquid concerned.

Since small particles, such as adsorbent particles for example, providea larger surface area than larger particles, efficiency is, notunexpectedly, better with the comparatively small particles. However,the small particles in a loose bed lead to a high pressure drop and,what is more, promote the formation of channels, which entails a certainrisk of break-through. Therefore, the particle size used in loose bedsis often but a compromise, meaning that usually the particle sizesoptimal for the particular application cannot be used. Moreparticularly, the need to achieve economical operating conditions, moreparticularly an acceptable pressure drop, often means that largerparticles (e.g., adsorbent particles) come to be used than would bedesirable for optimal utilization of the adsorption efficiency, so thatit is often the case that a considerable portion of the theoreticallyavailable capacity cannot be used.

DE 38 1.3 564 A1 and the same patent family's EP 0 338 551 A2 disclosean activated carbon filter layer for gasmasks which comprises a highlyair-pervious, substantially shape-stable three-dimensional supportingscaffold whereto a layer of granular, more particularly sphericalactivated carbon particles from 0.1 to 1 mm in diameter is fixed,wherein the supporting scaffold can be a braided structure formed ofwires, monofilaments or struts, or be a large-pore reticulatedpolyurethane foam. One disadvantage with the system described therein isthe fact that it requires an additional supporting material which has tobe endowed with the particles in question in a relatively costly andinconvenient operation. In addition, the particular choice of supportingscaffold then restricts the use in question.

DE 42 39 520 A1 discloses a high-performance filter which, consists of athree-dimensional supporting scaffold whereto adsorbent particles arefixed via a bonding material, wherein the supporting scaffold issheathed with a thermally stable and very hydrolysis-resistant plasticwhich amounts to about 20 to 500%, based on the scaffold. Moreparticularly, the supporting scaffold comprises a large-pore reticulatedpolyurethane foam sheathed with a silicone resin, polypropylene,hydrolysis-resistant polyurethane, an acrylate, a synthetic rubber orfluoropolymers. The manufacturing process for these structures isrelatively costly and inconvenient. In addition, the technologydescribed therein requires the presence of an additional supportingstructure.

DE 43 43 358 A1 discloses porous bodies comprising activated carbonwhich consist of plates and agglomerates formed from ground activatedcarbon incorporated in a porous SiO₂ matrix. What is more particularlydescribed therein are porous plates or bodies having adsorbingproperties, wherein activated carbon granules or activated carbonspherules, and/or granules or spherules comprising activated carbon, areadhered together by means of a silicate solution and subsequently thesilicate bridges are converted into silica gel bridges and the bodiesare dried. One disadvantage with this is the fixed geometry of theseporous bodies and also their lack of flexibility and compressibility,making them unsuitable for filtering conditions under mechanicalloading. A further disadvantage is that the particles comprisingactivated carbon are completely wetted with the silicate solution, sothat a large portion of the capacity of these particles is no longeravailable for adsorptive processes.

DE 43 31 586 02 discloses activated carbon agglomerates whereinactivated carbon particles between 0.1 to 5 mm in diameter are disposedand adhered around an approximately equal-sized particle of pitch byslight, pressure and heating and thereafter the pitch particle isrendered infusible and converted into activated carbon by oxidation, sothat the free interspace between the particles in the agglomerate has awidth amounting to at least 10% by volume of the particle size. Onedisadvantage with the particles described therein is the relativelycostly, high-energy production process and also the incompressibility ofthe agglomerates obtained. Owing to the rigidity of the activated carbonagglomerates, no use is contemplated for filter applications undermechanical loading. The lack of compressibility also means that furtherprocessing into molded parts by compression molding is not possible.

The same applies to the porous bodies having adsorbing properties as perDE 42 38 142 A1, which comprise adsorbent particles which areinterconnected via bridges of inorganic material, more particularlyargillaceous earth, wherein the void spaces between the adsorbentparticles comprise from 10 so 100% of the volume of the adsorbentparticles. Again, the porous bodies described therein have but littleflexibility and compressibility, foreclosing any use under mechanicalloading and any further processing into molded parts by compressionmolding.

BRIEF SUMMARY OF THE INVENTION

The problem addressed by the present invention is therefore that ofproviding adsorptive structures and adsorptive molded parts which atleast largely avoid or alternatively at least ameliorate theabove-described disadvantages of the prior art.

One particular problem addressed by the present invention is that ofproviding adsorptive structures and adsorptive molded parts which avoidor at least ameliorate the disadvantages of conventional granular-bedfilters based on individual particles, and also allow use undermechanical loading, more particularly have sufficient flexibility and/orcompressibility, so that further processing into adsorptive moldedparts, more particularly by compression molding, is made possible.

The problem as defined above is solved as proposed by the disclosureherein, which relates to the adsorptive structures of the presentinvention which are based on agglomerates of adsorbent particles;further, advantageous developments and embodifications of this aspect ofthe present invention are further provided.

The present invention further provides the process for producing theseadsorptive structures according to the present invention and as definedherein; further, advantageous developments and embodifications of thisaspect of the present invention are similarly provided.

The present invention further provides the present invention use of theadsorptive structures according to the present invention and as definedherein.

The present invention further provides a filter according to thedisclosure herein, which comprises the adsorptive structures of thepresent invention; further, advantageous developments andembodifications of the filter according to the present invention areprovided.

The present invention likewise relates to adsorptive molded parts and toa process for the production of these adsorptive molded parts and totheir use, and moreover to filters which comprise these adsorptivemolded parts.

It will be readily understood that embodifications, embodiments,advantages and the like as recited hereinbelow in respect of one aspectof the present invention only for the avoidance of repetition,self-evidently also apply mutatis mutandis to the other aspects of thepresent invention.

It will further be readily understood that ranges recited hereinbelowfor value, number and range recitations are not be construed aslimiting; a person skilled in the art will appreciate that in aparticular case or for particular use departures from the recited rangesand particulars are possible without leaving the realm of the presentinvention.

Having made that clear, the present invention will now be moreparticularly described.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides a magnified photographic illustration of adsorptivestructures of the present invention which are based on agglomerates ofadsorbent particles.

FIG. 2 provides a 200-fold microscopic magnification of an adsorptivestructure of the present invention which is based on an agglomerate ofadsorbent particles.

FIG. 3 provides a 500-fold microscopic magnification of an adsorptivestructure of the present invention which is based on an agglomerate ofadsorbent particles

FIG. 4 provides a graphic illustration of the dependency of thelength-based pressure drop in [Pa/cm] at a flow rate of 0.2 m/s on theagglomerate size in [mm] of various adsorptive structures of the presentinvention.

FIG. 5 provides a graphic illustration of the dependency of thelength-based pressure drop in [Pa/cm] at a flow rate of 0.2 m/s on thebed bulk density in [g/l] of various adsorptive structures of thepresent invention.

FIG. 6 provides time-dependent breakthrough curves of beds of variousadsorptive structures of the present invention as a function of theagglomerate size.

FIG. 7 provides a graphic illustration of the dependency of thelength-based pressure drop in [Pa/cm] at a flow rate of 0.2 m/s on theagglomerate size in [mm] of various adsorptive structures of the presentinvention.

FIG. 8 provides a graphic illustration of the dependency of thelength-based pressure drop in [Pa/cm] at a flow rate of 0.2 m/s on thebed bulk density in [g/1] of various adsorptive structures of thepresent invention.

FIG. 9 provides time-dependent breakthrough curves of beds of variousadsorptive structures of the present invention as a function of theagglomerate size

FIG. 10 provides a different geometric shape of adsorptive molded partsof the present invention, which are obtained by compression molding fromadsorptive structures of the present invention.

FIG. 11 provides a different geometric shape of adsorptive molded partsof the present invention, which are obtained by compression molding fromadsorptive structures of the present invention.

FIG. 12 provides a different geometric shape of adsorptive molded partsof the present invention, which are obtained by compression molding fromadsorptive structures of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention accordingly provides—in accordance with a firstaspect of the present invention—adsorptive structures based onagglomerates of adsorbent particles, wherein the individual agglomerateseach comprise a multiplicity of granular, preferably spherical adsorbentparticles, wherein the adsorptive structures are characterized

-   -   in that the adsorbent particles of an individual agglomerate are        bound together via a preferably thermoplastic organic polymer,        more particularly binder, and/or    -   in that the adsorbent particles of an individual agglomerate are        bound and/or adhered so a preferably thermoplastic organic        polymer, more particularly binder.

The term “agglomerates” as used in the realm of the present invention isto be understood as having a very broad meaning, and more particularlydesignates a more or less consolidated/conjoined accumulation ofpreviously loose constituents (i.e., individual adsorbent particles=baseparticles) to form a more or less firm ensemble. The term “agglomerates”in the realm of the present invention designates so to speak technicallyproduced conglomerations/accumulations of individual adsorbent particleswhich are conjoined together in the present case by an organic polymer.

The term “multiplicity of adsorbent particles” is to be understood inthe realm of the present invention as meaning more particularly at leasttwo and preferably more than two adsorbent particles.

In general, the organic polymer in she adsorptive structures of thepresent invention forms at least one core of the particular agglomerate.

More particularly, the adsorbent particles of an individual agglomerateare each disposed and/or lodged at one or more core of organic polymer,more particularly binder. The individual agglomerates may each compriseone or alternatively more cores of organic polymer, more particularlybinder.

The size of the core of organic polymer, more particularly binder, canvary within wide limits.

More particularly, the core of organic polymer, more particularlybinder, in the adsorptive structures according to she present inventionis from 100 to 2000 μm, more particularly from 150 to 1500 μm andpreferably from 200 to 1000 μm in size.

Typically, the size ratio of core of organic polymer, more particularlybinder, to individual adsorbent particle may be at least 1:1, moreparticularly at least 1.25:1, preferably at least 1.5:1, more preferablyat least 2:1 and even more preferably at least 3:1.

To ensure good adsorption efficiency, more particularly adsorptionkinetics and adsorption capacity, the individual agglomerates eachgenerally contain at least 5 adsorbent particles, more particularly atleast 10 adsorbent particles, preferably at least 15 adsorbent particlesand more preferably at least 20 adsorbent particles. The individualagglomerates may each comprise up to 50 adsorbent particles, moreparticularly up to 75 adsorbent particles and preferably up to 100adsorbent particles or more.

The weight ratio of adsorbent particles to organic polymeric theindividual agglomerates can similarly vary within wide limits. Ingeneral, the individual agglomerates each have a weight ratio ofadsorbent particles to organic polymer per agglomerate of at least 2:1,more particularly at least 3:1, preferably at least 5:1, more preferablyat least 7:1 and even more preferably at least 8:1. The individualagglomerates typically each have a weight ratio of adsorbent particlesto organic polymer per agglomerate in the range from 2:1 to 30:1, moreparticularly in the range from 3:1 to 20:1, preferably in the range from4:1 to 15:1 and more preferably in the range from 5:1 to 10:1. Theaforementioned lower limits are explained by the fact that a sufficientnumber or quantity of adsorbent particles has to be present to ensuresufficient adsorption efficiency, whereas the aforementioned upperlimits are occasioned by the need for the presence of a sufficientamount of organic polymer so ensure a stable ensemble or agglomerate.

In general, the individual agglomerates of the adsorptive structures ofthe present invention are in self-supporting form. This has theadvantage that no additional support is required.

In general, the individual agglomerates of the adsorptive structures ofthe present invention are in particulate form. The particle sizes of theindividual agglomerates can vary within wide limits. More particularly,the individual agglomerates of the adsorptive structures of the presentinvention may have particle sizes, more particularly particle diameters,in the range from 0.01 to 20 mm, more particularly in the range from0.05 to 15 mm, preferably in the range from 0.1 to 10 mm, morepreferably in the range from 0.2 to 7.5 mm and even more preferably inthe range from 0.5 to 5 mm. The aforementioned particle size particularsare absolute particle sizes.

Typically, the individual agglomerates of the adsorptive structures ofthe present invention each have a raspberry- or blackberrylikestructure. Individual outer adsorbent particles are disposed about oneor more inner cores of organic polymer.

Advantageously, the organic polymer used is in thermoplastic form.Typically, the organic polymer is further in heat-tacky form.Preferably, the organic polymer is selected from polymers from the groupof polyesters, polyamides, polyethers, polyetheresters and/orpolyurethanes and also their mixtures and copolymers.

The organic polymer preferably comprises a preferably thermoplasticbinder, more particularly a preferably thermoplastic adhesive,preferably based on polymers from the group of polyesters, polyamides,polyethers, polyetheresters and/or polyurethanes and also their mixturesand copolymers.

The organic polymer, more particularly the binder, preferably thehot-melt adhesive, is typically solid at 25° C. and atmosphericpressure.

Typically, the organic polymer, more particularly the binder, preferablythe hot-melt adhesive, has a melting or softening range above 100° C.,preferably above 110° C. and more particularly above 120° C. In general,the organic polymer, more particularly the binder, preferably thehot-melt adhesive, has a thermal stability temperature of at least 100°C., preferably at least 125° C. and more particularly at least 150° C.

To ensure good adsorption efficiency, more particularly adsorptionkinetics and/or adsorption capacity, it is advantageous for theadsorbent particles of the individual agglomerates to be covered and/orcoated with organic polymer to at most 50%, more particularly to at most40%, preferably to at most 30% and more preferably to at most 20% oftheir surface. A certain degree of coverage of the surface is required,however, to ensure good adherence of the adsorbent particles to theorganic polymer.

The adsorbent particles typically have a porous structure. The adsorbentparticles, as mentioned, are further in granular, more particularlyspherical, form. This provides a very high surface area for adsorptionand ensures good mechanical loadability and also goodfixability/adherability.

The particle sizes of the adsorbent particles can similarly vary withinwide limits. Typically, the adsorbent particles have absolute particlesizes, more particularly absolute particle diameters, in the range from0.001 to 3 mm, more particularly in the range from 0.005 to 2.5 mm,preferably in the range from 0.01 to 2 mm, more preferably in the rangefrom 0.02 to 1.5 mm and even more preferably in the range from 0.05 to 1mm.

The median particle sizes of the adsorbent particles can similarly varywithin wide limits. Generally, the adsorbent particles have medianparticle sizes, more particularly median particle diameters (D50), inthe range from 0.01 to 2 mm, more particularly in the range from 0.05 to1.5 mm and preferably in the range from 0.1 to 1 mm.

The adsorbent particles may consist of a material selected from thegroup of activated carbon; zeolites; inorganic oxides, more particularlysilicon dioxides, silica gels and aluminum oxides; molecular sieves;mineral granulates; klathrates; metal-organic framework materials (MOFs)and also their mixtures. Activated carbon is particularly preferred.

In a particularly preferred embodiment, the adsorbent particles areformed from granular, more particularly spherical, activated carbon.

To ensure good adsorption efficiency, it is of advantage for theadsorbent particles of the present invention to have a specific surfacearea (BET surface area) of at least 500 m²/g, more particularly at least750 m²/g, preferably at least 1000 m²/g and more preferably at least1200 m²/g. Typically, the adsorbent particles have a specific surfacearea (BET surface area) in the range from 500 to 4000 m²/g, moreparticularly in the range from 750 to 3000 m²/g, preferably in the rangefrom 900 to 2500 m²/g and more preferably in the range from 950 to 2000m²/g.

The adsorbent particles used according to the present invention shouldfurther possess good mechanical loadability. Typically the adsorbentparticles, more particularly the activated carbon particles, preferablythe activated carbon granules or activated carbon spherules, have abursting pressure of at least 5 newtons, more particularly a burstingpressure in the range from 5 newtons to 50 newtons, per particle.

To ensure good adsorption efficiencies, the adsorbent particles usedshould further have high adsorption volumes, high Gurvich total porevolumes, high total porosities and also high specific total porevolumes.

Typically, the adsorbent particles, used according to the presentinvention have an adsorption volume V_(ads) of at least 250 cm³/g, moreparticularly at least 300 cm³/g, at least 350 cm³/g and more preferablyat least 400 cm³/g. The adsorbent particles used according to thepresent invention typically have an adsorption volume V_(ads) in therange from 250 to 3000 cm³/g, more particularly in the range from 300 to2000 cm³/g and preferably in the range from 350 to 2500 cm³/g.

The adsorbent particles used according to the present inventiontypically further have a Gurvich total pore volume of at least 0.50cm³/g, more particularly at least 0.55 cm³/g, preferably at least 0.60cm³/g, more preferably at least 0.65 cm³/g and even more preferably atleast 0.70 cm³/g. The adsorbent particles used according to the presentinvention typically have a Gurvich total pore volume in the range from0.50 to 2.0 cm³/g, more particularly in the range from 0.55 to 1.5cm³/g, preferably in the range from 0.60 to 1.2 cm³/g and morepreferably in the range from 0.65 to 1.0 cm³/g.

The adsorbent particles used according to the present invention furtherhave a high total porosity. Typically, the adsorbent particles have atotal porosity in the range from 10% to 80%, more particularly in therange from 20% to 75% and preferably in the range from 25% to 70%.

Finally, the adsorbent particles used according to the present inventionhave a high specific total pore volume. The adsorbent particlestypically have a specific total pore volume in the range from 0.01 to1.0 cm³/g, more particularly in the range from 0.1 to 3.0 cm³/g, andpreferably in the range from 0.2 to 2.0 cm³/g. The proportion of poreshaving pore diameters≦75 Å can preferably be at least 65%, moreparticularly at least 70% and preferably at least 75%.

Preferably used adsorbent particles having the aforementionedproperties, more particularly based on spherical activated carbon, areavailable from Blücher GmbH, Erkrath, Germany or from Adsor-Tech GmbH,Premnitz, Germany.

According to a particular embodiment of the present invention, theadsorptive structures of the present invention and/or the agglomeratesforming said structures can be processed into a molded part, which canbe done via compression molding in particular.

It is a particular advantage of the adsorptive structures that they havea distinctly reduced pressure drop compared with a loose bed ofindividual adsorptive particles. The adsorptive structures of thepresent invention, more particularly in the form of a loose bed or inthe form of a molded part, thus have a length-based pressure drop at aflow rate of 0.2 m/s of at most 200 Pa/cm, more particularly at most 150Pa/cm, preferably at most 100 Pa/cm, more preferably at most 90 Pa/cm,even more preferably at most 70 Pa/cm and yet even more preferably atmost 50 Pa/cm. Usually, the adsorptive structures of the presentinvention, in the form of a loose bed or in the form of a molded part,have a length-based pressure drop at a flow rate of 0.2 m/s in the rangefrom 5 to 200 Pa/cm, more particularly in the range from 5 to 150 Pa/cm,preferably in the range from 5 to 100 Pa/cm, more preferably in therange from 7.5 to 90 Pa/cm and even more preferably in the range from 10to 80 Pa/cm. In comparison thereto, loose beds of similar adsorbentparticles, as are used in the adsorptive structures of the presentinvention, typically have length-based pressure drops at a flow rate of0.2 m/s in the range from 200 to 600 Pa/cm.

The present invention thus makes it possible to convert granular orspherical adsorbents or adsorbent particles, but also other forms ofadsorbents, with the assistance of organic polymers, more particularlybinders or hot-melt adhesives, into agglomerates which, in a loose bedbut also when compression molded into an adsorptive molded part, have avery low differential pressure, especially compared with, for example,loose beds of comparable granular or spherical adsorbents or adsorbentparticles or splint coal. The adsorptive agglomerates according to thepresent invention are therefore particularly useful in applicationswhere both a low differential pressure and a low initial breakthroughare crucial.

The present invention is accordingly associated with a multiplicity ofadvantages, of which only some are mentioned above and some further arehereinbelow enumerated in a nonlimiting and nonconclusive manner:

As mentioned, the adsorptive structures or agglomerates according to thepresent invention in the form of a loose bed have a distinctly reduceddifferential pressure compared with purely base adsorbent particleswithout other adsorption properties, for example adsorption kinetics,adsorption capacity, initial breakthrough or the like, being impaired.

The adsorptive structures or agglomerates of the present inventionfurther combine good mechanical stabilities with good flexibility andcompressibility, so that the adsorptive structures or agglomerates ofthe present invention are readily compression moldable and processableinto corresponding stable and self-supporting adsorptive molded parts ofany desired geometry, as described in detail hereinbelow.

The adsorptive structures or agglomerates of the present inventionprovide a very high degree of activation and hence a very high capacityon the part of the base adsorbent particles coupled with very goodmechanical stability; agglomerate formation does not involve anysignificant reduction in mechanical stability, compared with thenonagglomerated base adsorbent particles, and this at very high retaineddegrees of activation, as is the case for the nonagglomerated baseadsorbent particles.

The adsorptive structures or agglomerates of the present invention alsoprovide a high total adsorption efficiency even at low adsorbateconcentrations due to very high possible adsorption potentials on thepart of the base adsorbent particles.

Owing to the very pure surfaces of the base adsorbent particles, highrelative humidities are not observed to result in significant drops inefficiency.

Owing to the high hardness of the base adsorbent particles underabrasion, attrition and loading, the adsorptive structures oragglomerates of the present invention are at least substantiallydustless and more particularly contain at least substantially norespiratory dust particle sizes.

In addition, the adsorptive structures or agglomerates of the presentinvention retain the excellent impregnatability of the base particles(more than 60% in the wetting test, for example).

In addition, a high broad-spectrum efficacy of adsorption is achievedthrough an efficient pore size distribution (combination of very highmicro- and meso/macropore volumes, for example) adjustable in the courseof the manufacturing operation of the base adsorbent particles, as wellas very good impregnatability on the part of the base adsorbentparticles. The adsorptive structures or agglomerates of the presentinvention make it possible for example to combine adsorbent particleshaving different pore size distributions with each other within a singleagglomerate, distinctly improving the broad-spectrum efficacy ofadsorption.

The pressure drop is freely adjustable via free choice of theagglomerate fraction in the range of the base adsorbent particlediameters up to the agglomerate diameters.

As mentioned, a distinctly lower pressure drop is observed for a loosebed of the adsorptive, structures or agglomerates of the presentinvention compared with granular or molded activated carbons at the sameadsorption capacity.

The overall adsorption efficiency and the overall adsorption kineticsare adjustable/controllable via free choice of the base adsorbentparticle size (alterable surface/volume ratio, for example) and via freechoice of the degree of base adsorbent particle activation (alterablepore size distribution, for example).

Similarly, bed bulk density and capacity for a given pressure drop areadjustable for example via free choice of the base adsorbent particlesize (alterable surface/volume ratio, for example).

The high buffer volume compensates any reduced adsorption due to theorganic polymeric constituents, more particularly hot-melt adhesiveconstituents, and so there is no significant to no blocked pore volumedue to the organic polymeric constituents. Any capacity loss due to theconstituents of the organic polymer is extremely small.

The present invention further provides—in accordance with a secondaspect of the present invention—a process for producing theabove-described adsorptive structures of the present invention which arebased on agglomerates of adsorbent particles, wherein the presentinvention production process for the adsorptive structures according tothe present invention comprises

-   a) first granular, preferably spherical adsorbent particles on the    one hand and particles of preferably thermoplastic organic polymer,    more particularly binder, on the other being brought into contact    and mixed,-   b) then heating the resulting mixture to temperatures above the    melting or softening temperature of the organic polymer, and-   c) finally cooling the resulting product to temperatures below the    melting or softening temperature of the organic polymer.

Typically, step b) comprises maintaining the attained temperature for adefined period, more particularly for at least one minute, preferably atleast 5 minutes, preferably at least 10 minutes. Typically, the attainedtemperature is maintained for a period in the range from 1 to 600minutes, more particularly in the range from 5 to 300 minutes andpreferably in the range from 10 to 150 minutes. The criterion fordetermining the maintaining time is that the entire batch is brought toa unitary temperature and all the organic polymer, more particularly allthe hot-melt adhesive, has completely melted.

In general, during the performance of step b), more particularly in thecourse of the aforementioned heating and/or maintaining operation, anenergy input, preferably via mixing, takes place, more particularlywherein the energy input is used to control the resulting agglomeratesize, in which case a small agglomerate size is obtained with increasingenergy input.

Typically, the present invention process is performed in a heatablerotary tube, more particularly a rotary tube oven. The rotary speed ofthe rotary tube is used to control particularly the energy inputment andthus the resulting agglomerate size; increasingly smaller agglomeratesizes are obtainable with increasing rotary speed. Batchwise emptying ofthe rotary tube then makes it possible to obtain altogether multimodalagglomerate size distributions by varying the rotary speeds for theindividual batches.

In a preferred embodiment of the present invention, the agglomeratesresulting in step c) may be processed in a subsequent step d) into anadsorptive molded part, which can be done by compression molding inparticular. The processing into molded parts can advantageously beeffected by heating, in which, case it is preferable to set temperaturesbelow the melting or softening temperature of the organic polymer, moreparticularly of the hot-melt adhesive, so that the agglomeratesconcerned are not decomposed and/or do not disintegrate.

In the realm of the present invention production process for theadsorptive structures or agglomerates of the present invention, thethermoplastic organic polymer, more particularly binder, preferablyhot-melt, adhesive, is typically used in the form of particles, moreparticularly granular or spherical particles, preferably in the form ofparticles solid at room temperature and atmospheric pressure. Theorganic polymer can typically be used with particle sizes in the rangefrom 100 to 2000 μm, more particularly in the range from 150 to 1500 μmand preferably in the range from 200 to 1000 μm. The size ratio oforganic polymer particles to adsorbent particles can typically be chosenat not less than 1:1, more particularly at not less than 1.25:1,preferably at not less than 1.5:1, more preferably at not less than 2:1and even more preferably at not less than 3:1.

In the realm of the present invention production process, the weightratio of adsorbent particles to organic polymer may typically be atleast 2:1, more particularly at least 3:1, preferably at least 5:1, morepreferably at least 7:1 and even more preferably at least 8:1. Theweight ratio of adsorbent particles to organic polymer typically variesin the range from 2:1 to 30:1, more particularly in the range from 3:1to 20:1, preferably in the range from 4:1 to 15:1 and more preferably inthe range from 5:1 to 10:1.

As mentioned, the organic polymer used is a preferably thermoplasticbinder, more particularly a preferably thermoplastic hot-melt, adhesive,preferably based on polymers, from the group of polyesters, polyamides,polyethers, polyetheresters and/or polyurethanes and their mixtures andcopolymers.

For further details concerning the present invention process, referencecan be made to the above observations concerning the present inventionadsorptive structures, which apply mutatis mutandis in respect of thepresent invention production process.

In a typical embodiment of the present invention, the followingprocedure can be adopted for example: The organic polymer used, asmentioned, typically comprises hot-melt adhesives, preferably in theform of so-called powder adhesives, in which case a multiplicity ofadhesives can be used. Typical particle sizes for the adhesives usedvary in the range from 200 to 1000 μm. It is preferable to use adhesivesof high thermal and chemical stability.

Particular preference is given to using thermoplastic adhesives, moreparticularly hot-melt adhesives. It is possible to use adhesives havingpolyester, polyamide or polyurethane hard segments, which may alsocontain soft segments, in which case the soft segments can be selectedfrom the classes of the (poly) ethers and (poly)esters. The typicalpolymer designations are then, for example, copolyesters or specificpolyetherester.

As mentioned, the hot-melt adhesives are preferably used in powder form.The particle size distribution of the adhesives should be greater thanthe particle size distribution of the base adsorbent particles in orderthat a downward descent of adhesive constituents in the bed isprevented.

As mentioned, the powder adhesive particles on the one hand and the baseadsorbent particles on the other can then be initially charged to arotary tube and intensively mixed therein and the mixture heated abovethe softening or melting temperature of the adhesive and maintained fora defined period at that temperature. The thermal treatment is dependenton the particular adhesive used. Mechanical treatment, more particularlythe rotary speed of the rotary tube, can be used so influence theresulting size of agglomerate.

Agglomeration depends on the type of adhesive used. As mentioned, anydesired adhesives can be used in principle. The target temperatureshould be greater than or within the melting or softening temperaturerange of the adhesive.

Care should further be taken to ensure that a dumped bed be heated tothe target temperature in the course of the present invention process,and that appropriate defined maintaining times be used in order thatcomplete heating of the entire dumped bed may be achieved.

The target temperature should be chosen as low as possible, since anyfurther temperature elevation and thus any further reduction in theviscosity of the adhesive, once the melting or softening temperature ofthe present adhesive is reached, would lead to an increased and thusundesired pore blocking of the adsorbent particles.

The mechanical treatment, more particularly the rotary speed of therotary tube reactor, depends on the desired agglomerate sizedistribution. Elevated rotary speed can be used to exert a definedinfluence on the agglomerate size distribution. An elevated rotary speedleads to a smaller agglomerate size distribution.

The present invention further provides—in accordance with a third aspectof the present invention—the present invention use of the adsorptivestructures according to the present invention.

The adsorptive structures according to the present invention can thus beused for the adsorption of toxics, noxiants and odors, more particularlyfrom gas or air streams or alternatively from liquids, more particularlywater. The adsorptive structures of the present invention can further beused for cleaning or purifying gases, gas streams or gas mixtures, moreparticularly air, or liquids, more particularly water. The adsorptivestructures of the present invention can further be used in adsorptionfilters. The adsorptive structures of the present invention can furtherbe used in the manufacture of filters, more particularly adsorptionfilters. The adsorptive structures of the present invention can be usedfor the production of adsorptive molded parts, more particularly bycompression molding. The adsorptive structures of the present inventioncan finally be used as a sorption store for gases, more particularlyhydrogen.

In a typical embodiment of the present invention, the adsorptivestructures of the present invention can be used in the form of a loosebed. As an alternative thereto, the adsorptive structures according tothe present invention can, however, also be used in the form of anadsorptive molded part produced therefrom, more particularly viacompression molding.

For further details concerning the present invention use, reference canbe made to the above observations concerning the adsorptive structuresof the present invention and concerning the production process thereof,which apply mutatis mutandis in respect of the present invention use.

The present invention further provides—in accordance with a fourthaspect of the present invention—a filter comprising adsorptivestructures based on agglomerates of adsorbent particles, moreparticularly as described above, preferably in the form of a loose bed,wherein the filter has a length-based pressure drop at a flow rate of0.2 m/s of at most 200 Pa/cm and more particularly in the range from 5to 200 Pa/cm. More particularly, the filter of the present invention hasa length-based pressure drop at a flow rate of 0.2 m/s of at most 150Pa/cm, preferably at most 100 Pa/cm, more preferably at most 90 Pa/cm,even more preferably at most 70 Pa/cm and yet even more preferably atmost 50 Pa/cm. Usually, the filter of the present invention has alength-based pressure drop at a flow rate of 0.2 m/s in the range from 5to 150 Pa/cm, prefer ably in the range from 5 to 100 Pa/cm, morepreferably in the range from 7.5 to 90 Pa/cm and even more preferably inthe range from 10 to 80 Pa/cm.

For further details concerning the filter of the present invention,reference can be made to the above observations concerning theadsorptive structures of the present invention and the process for theproduction thereof and concerning the use thereof, which apply mutatismutandis in respect of the filter of the present invention.

The present invention also further provides—in accordance with a fifthaspect of the present invention—an adsorptive molded part constructedfrom a multiplicity of adsorptive structures based on agglomerates ofadsorbent particles, more particularly as defined above.

The adsorptive molded part of the present invention comprises amultiplicity of granular, preferably spherical adsorbent particles. Theadsorbent particles therein may be at least partly bound together via apreferably thermoplastic organic polymer, more particularly binder,and/or the adsorbent particles may be at least partly bound and/oradhered to a preferably thermoplastic organic polymer, more particularlybinder.

Preferably, the adsorptive molded part of the present invention is inone-piece and/or monolithic form. The adsorptive molded part accordingto the present invention may otherwise have any desired geometric forms.For instance, the adsorptive molded part of the present invention may bein cylindrical, rod-shaped, plate-shaped, cube-shaped, polyhedral or thelike form.

The adsorptive molded part of the present invention has an excellentpressure drop. More particularly, the adsorptive molded part of thepresent invention has a length-based pressure drop at a flow rate of 0.2m/s of at most 200 Pa/cm, more particularly at most 150 Pa/cm,preferably at most 100 Pa/cm, more preferably at most 90 Pa/cm, evenmore preferably at most 70 Pa/cm and yet even more preferably at most 50Pa/cm. Typically, the adsorptive molded part of the present inventionhas a length-based pressure drop at a flow rate of 0.2 m/s in the rangefrom 5 to 200 Pa/cm, more particularly in the range from 5 to 150 Pa/cm,preferably in the range from 5 to 100 Pa/cm, more preferably in therange from 7.5 to 90 Pa/cm and even more preferably in the range from 10to 80 Pa/cm.

The adsorptive molded part of the present invention is more particularlyobtainable from the adsorptive structures of the present invention whichare based on agglomerates of adsorbent particles, more particularly asdescribed above, more particularly by compression molding the adsorptivestructures of the present invention.

For further details concerning the adsorptive molded parts of thepresent invention, reference can be made to the above observationsconcerning the other aspects of the invention, which apply mutatismutandis in respect of the adsorptive molded parts according to thepresent invention.

The present invention further provides—in accordance with a sixth aspectof the present invention—a process for producing an adsorptive moldedpart as described above, wherein adsorptive structures based onagglomerates of adsorbent particles, more particularly as describedabove, are compression molded in the course of this process. Typically,compression molding is effected by heating, preferably by heating totemperatures below the melting or softening temperature of the organicpolymer. Typically, the compression molding is effected by simultaneousshaping.

For further details concerning the present invention production processfor the present invention adsorptive molded part, reference can be madeto the above observations concerning the other aspects of the presentinvention, which apply mutatis mutandis in respect of the presentinvention adsorptive molded part.

The present invention further provides—in accordance with a seventhaspect of the present invention—the use of the present inventionadsorptive molded part.

The adsorptive structures according to the present invention can thus beused for the adsorption of toxics, noxiants and odors, more particularlyfrom gas or air streams or alternatively from liquids, more particularlywater. The adsorptive molded part of the present invention can furtherbe used for cleaning or purifying gases, gas streams or gas mixtures,more particularly air, or liquids, more particularly water. Theadsorptive molded part of the present invention can further be used inadsorption filters. The adsorptive molded part of the present inventioncan further be used in the manufacture of filters, more particularlyadsorption filters. The adsorptive molded part of the present inventioncan finally be used as a sorption store for gases, more particularlyhydrogen.

For further details concerning the present invention, use of the presentinvention adsorptive molded part, reference can be made to the aboveobservations concerning the other aspects of the invention because theyapply mutatis mutandis in respect of this aspect of the presentinvention.

The present invention further provides—in accordance with a eighthaspect of the present invention—a filter comprising an adsorptive moldedpart according to the present invention, wherein the filter has alength-based pressure drop at a flow rate of 0.2 m/s of at most 200Pa/cm and more particularly in the range from 5 to 200 Pa/cm. Moreparticularly, the filter of the present invention has a length-basedpressure drop at a flow rate of 0.2 m/s of at most 150 Pa/cm, preferablyat most 100 Pa/cm, more preferably at most 90 Pa/cm, even morepreferably at most 70 Pa/cm and yet even more preferably at most 50Pa/cm. Typically, the filter of the present invention has a length-basedpressure drop at a flow rate of 0.2 m/s in the range from 5 to 150Pa/cm, preferably in the range from 5 to 100 Pa/cm, more preferably inthe range from 7.5 to 90 Pa/cm and even more preferably in the rangefrom 10 to 80 Pa/cm.

For further details concerning the filter of the present invention,reference can be made to the above observations, concerning the otheraspects of the present invention because they apply mutatis mutandis inrespect of this aspect of the present invention.

Further advantageous properties, aspects and features of the presentinvention will be apparent from the following description of exemplaryembodiments illustrated herein.

Further elaborations, modifications and variations of the presentinvention will be readily apparent to and realizable by the ordinarilyskilled on reading the description without their having to go outsidethe realm of the present invention.

The present invention is illustrated by the following exemplaryembodiments which, however, shall in no way limit the present invention.

Exemplary Embodiments

The production of adsorptive structures based on agglomerates ofadsorbent particles and also of adsorptive molded parts which areobtainable therefrom will now be described.

The production of the adsorptive structures or agglomerates of thepresent invention proceeds by spherical adsorbent particles based onactivated carbon (obtainable for example from Blücher GmbH, Erkrath,Germany or from Adsor-Tech GmbH, Premnitz, Germany) on the one handbeing first brought into contact with each other and thermoplastichot-melt adhesive particles, generally with particle sizes in the rangefrom 200 to 1000 μm (for example copolyester hot-melt adhesives fromEMS-Chemie AG, EMS-GRILTECH, Switzerland) on the other being broughtinto contact with each other and mixed in a rotary tube and subsequentlyheated therein above the melting or softening temperature of thehot-melt adhesive concerned and maintained therein at this temperaturefor a defined period, and finally the resulting product being cooleddown below the melting or softening temperature of the hot-melt adhesiveconcerned. Hot-melt adhesives suitable for the purposes of the presentinvention have for example the following properties: melting range: 118to 123° C., melt viscosity: 350 mPas, lamination temperature: 120 to150° C., heat resistant to 100° C., wash resistant to 75° C.

The present invention process is carried out in a heatable rotary tubeby controlling the energy input and thus the resulting size ofagglomerate via the rotary speed of the rotary tube.

The resulting agglomerates of the present invention are subsequentlyanalyzed and assessed. Relevant examples of the adsorptive structures ofthe present invention are shown in FIGS. 1 to 3. Part of the adsorptivestructures or agglomerates obtained in this way are further processedinto adsorptive molded parts according to the present invention, bycompression molding with simultaneous shaping by heating below themelting or softening temperature of the hot-melt adhesive concerned.Adsorptive molded parts according to the present invention result.Relevant examples are depicted in FIGS. 10 to 12.

Exemplary Production of Aggolmerates 1

Starting materials:

-   -   base adsorbent particles; spherical activated carbon,        polydisperse, fine, grain size<0.315 mm.    -   thermoplastic hot-melt adhesive, grain size 200 to 1000 μm    -   adhesive use ratio by weight:1:5 (adhesive:base particles)    -   target temperature: T=175° C.    -   maintaining time on attainment of target temperature: t=30 min    -   rotary tube reactor rotary speed: n=1 rpm

The table which follows reports the weight-specific adhesive content andthe weight-specific butane adsorption by way of example in respect ofthe agglomerates formed. The example test is carried out redundantly.

TABLE 1 weight-specific adhesive content, weight-specific butaneadsorption (BA adsorption) Sample Adhesive constituents [%] BAadsorption [%] Example 1 12.0 25.7 Example 2 12.1 25.6

The agglomerates formed are divided into the following sieve fractions:

-   -   0.6-1.0 mm (agglomerates I)    -   0.8-1.25 mm (agglomerates II)    -   1.25-2.5 mm (agglomerates III)

Table 2 hereinbelow reports by way of example values determined on thesieved-off agglomerates.

TABLE 2 values determined on sieved-off agglomerates Pressure Beddensity drop with Bed density Fraction per length adhesive Adhesivewithout adhesive tested (v = 0.2 m/s) constituents constituentsconstituents [mm] [Pa/cm] [g/l] (%) [g/l] 0.6-1.0 62 442 11.2 3920.6-1.0 69 462 11.2 410  0.8-1.25 40 411 11.6 363  0.8-1.25 40 409 11.6362 1.25-2.5  15 329 12.7 287 1.25-2.5  16 317 12.7 277

The diagrams as per FIGS. 4 and 5 are exemplary illustrations of thecourse of pressure drop against, agglomerate size (FIG. 4) and of thecourse of pressure drop against bulk density with adhesive constituents(FIG. 5).

The diagram as per FIG. 6 is an exemplary illustration of breakthroughcurves (toluene) of various agglomerates of the present inventiondiffering in size (flow rate: v=0.1 m/s; initial concentration c=80 ppmof toluene; relative humidity 50%; temperature T=23° C.; bed height h=20mm).

Table 3 hereinbelow shows measured results and parameters of thebreakthrough curves compared with conventional activated carbon filtersby way of example. Beds of agglomerates of the present inventiondiffering in agglomerate size (agglomerated base adsorbent particles of<0.315 mm) are compared with beds of conventional activated carbonparticles (comparative example; particle size: 0.8 to 1.7 mm).

TABLE 3 measured results and parameters of breakthrough curves comparedwith conventional activated carbon filters Conventional activated carbonAgglomerate Agglomerate Agglomerate filter Sample I II III (comparator)size [mm] 0.6-1.0 0.8-1.25 1.25-2.5 0.8-1.7 bed height 20.0 20.0 20.020.0 [mm] bed diameter 50.0 50.0 50.0 50.0 [mm] bed volume 39.3 39.339.3 39.3 [ml] bed weight [g] 17.9 16.1 12.9 21.9 bed density 0.5 0.40.3 0.6 [g/cm³] toluene 79.4 79.8 79.3 80.2 concentration [ppm]temperature 23.0 23.2 23.2 22.7 [° C.] rel. humidity 49.9 49.9 49.9 49.9[%] flow rate 0.1 0.1 0.1 0.1 (target value) [m/s] pressure drop 53.833.2 9.1 58.0 [Pa] breakthrough [%]/ time [min]   1 0.1 0.0 0.0 0.0   50.1 0.0 0.0 0.0  10 0.1 0.0 0.0 0.0  30 0.1 0.1 0.1 0.0  60 0.1 0.1 0.10.1  120 0.1 0.1 0.1 0.1  180 0.1 0.1 0.1 0.1  240 0.1 0.1 0.1 0.1  3600.1 0.1 0.2 0.1  600 0.1 0.1 0.4 0.2  900 0.3 0.5 1.1 0.7 1200 0.8 1.213.3 18.8 time [min] to breakthrough [%]  5 1649.3 1344.0 1100.5 1084.310 1715.7 1385.1 1172.3 1150.3 30 1799.3 1460.7 1286.3 1230.9

Exemplary Production of Agglomerates 2

Starting materials:

-   -   base adsorbent particles; spherical activated carbon,        polydisperse, course, grain size 0.56-0.71 mm    -   thermoplastic hot-melt adhesive, grain size 500 to 1000 μm    -   adhesive use ratio by weight:1:10 (adhesive:base particles)    -   target temperature: T=175° C.    -   maintaining time on attainment of target temperature: t=30 min    -   rotary tube reactor rotary speed: n=1 rpm.

The table which follows reports the weight-specific adhesive content andthe weight-specific butane adsorption by way of example in respect ofthe agglomerates formed. The example test is carried out redundantly.

TABLE 4 weight-specific adhesive content, weight-specific butaneadsorption (BA adsorption) Sample Adhesive constituents [%] BAadsorption [%] Example 1 6.8 30.7 Example 2 4.8 32.4

The agglomerates formed are divided into the following sieve fractions:

-   -   0.8-1.25 mm (agglomerates I′)    -   1.25-2.5 mm (agglomerates I″)    -   2.5-5.0 mm (agglomerates I′″)

Table 5 hereinbelow reports by way of example values determined on thesieved-off agglomerates.

TABLE 5 values determined on sieved-off agglomerates Pressure Beddensity drop Bed density without Fraction per length with adhesiveAdhesive adhesive tested (v = 0.20 m/s) constituents constituentsconstituents [mm] [Pa/cm] [g/l] (%) [g/l]  0.8-1.25 55 485 2.7 472 0.8-1.25 64 482 2.7 469 1.25-25   20 384 4.6 366 1.25-25   21 392 4.6374 2.5-5.0 9 290 5.6 274 2.5-5.0 9 290 5.6 274

The diagrams as per FIGS. 6 and 7 are exemplary illustrations of thecourse of pressure drop against agglomerate size (FIG. 6) and of thecourse of pressure drop against bulk density with adhesive constituents(FIG. 7).

The diagram as per FIG. 8 is an exemplary illustration of breakthroughcurves (toluene) of various agglomerates of the present inventiondiffering in size (flow rate: v=0.1 m/s; initial concentration c=80 ppmof toluene; relative humidity 50%; temperature T=23° C.; bed height h=20mm).

Table 6 hereinbelow shows measured results and parameters of thebreakthrough curves compared with conventional activated carbon filtersby way of example. Beds of agglomerates of the present inventiondiffering in agglomerate size (agglomerated base adsorbent particles of0.56-0.71 mm) are compared with beds of conventional activated carbonparticles (comparative example; particle size: 0.8 to 1.7 mm).

TABLE 6 measured results and parameters of breakthrough curves comparedwith conventional activated carbon filters Conventional activatedAgglomerate Agglomerate Agglomerate carbon filter Sample I′ II′ III′(comparator) size [mm] 0.8-1.25 1.25-2.5 2.5-5.0 0.8-1.7 mm bed height20.0 20.0 20.0 20.0 [mm] bed diameter 50.0 50.0 50.0 50.0 [mm] bedvolume 39.3 39.3 39.3 39.3 [ml] bed weight [g] 19.0 15.1 11.4 21.9 beddensity 0.5 0.4 0.3 0.6 [g/cm³] toluene 79.4 81.9 80.2 80.2concentration [ppm] temperature 22.9 22.9 22.7 22.7 [° C.] rel. humidity49.9 49.9 49.9 49.9 [%] flow rate 0.1 0.1 0.1 0/1 (target value) [m/s]pressure drop 39.5 10.7 3.1 58.0 [Pa] breakthrough [%]/time [min]   10.0 0.0 0.4 0.0   5 0.0 0.0 0.4 0.0  10 0.0 0.0 0.4 0.0  30 0.0 0.0 0.40.0  60 0.0 0.0 0.5 0.1  120 0.0 0.0 0.7 0.1  180 0.0 0.0 0.9 0.1  2400.0 0.0 1.2 0.1  360 0.0 0.1 2.1 0.1  600 0.1 0.2 6.0 0.2  900 0.1 0.621.9 0.7 1200 0.3 2.2 56.2 18.8 time [min] to breakthrough [%]  5 1718.51347.6 561.7 1084.3 10 1774.3 1440.1 714.3 1150.3 30 1875.5 1582.5 984.71230.9

1. An adsorptive structure based on agglomerates of adsorbent particles,wherein the individual agglomerates each comprise a multiplicity ofgranular, preferably spherical adsorbent particles, characterized inthat the adsorbent particles of an individual agglomerate are boundtogether via a preferably thermoplastic organic polymer, moreparticularly binder, and/or in that the adsorbent particles of anindividual agglomerate are bound and/or adhered to a preferablythermoplastic organic polymer, more particularly binder.
 2. Theadsorptive structure according to claim 1, characterized in that theorganic polymer forms at least one core of the particular agglomerateand/or in that the adsorbent particles of an individual agglomerate areeach disposed and/or lodged at one or more core of organic polymer, moreparticularly binder, more particularly wherein the individual,agglomerates may each comprise one or more cores of organic polymer,more particularly binder.
 3. The adsorptive structure according to claim2, characterized in that the core of organic polymer, more particularlybinder, has a size in the range from 100 to 2000 μm, more particularlyin the range from 150 to 1500 μm and preferably in the range from 200 to1000 μm, and/or in that the size ratio of core of organic polymer, moreparticularly binder, to individual adsorbent particle is at least 1:1,more particularly at least 1.25:1, preferably at least 1.5:1, morepreferably at least 2:1 and even more preferably at least 3:1.
 4. Theadsorptive structure according to any preceding claim, characterized inthat the individual agglomerates each comprise at least 5 adsorbentparticles, more particularly at least 10 adsorbent particles, preferablyat least 15 adsorbent particles and more preferably at least 20adsorbent particles, and/or in that the individual agglomerates eachcomprise up to 50 adsorbent particles, more particularly up to 75adsorbent particles and preferably up to 100 adsorbent particles ormore.
 5. The adsorptive structure according to any preceding claim,characterized in that the individual agglomerates each have a weightratio of adsorbent particles to organic polymer per agglomerate of asleast 2:1, more particularly at least 3:1, preferably at least 5:1, morepreferably at least 7:1 and even more preferably at least 8:1, and/or inthat the individual agglomerates each have a weight ratio of adsorbentparticles to organic polymer per agglomerate in the range from 2:1 to30:1, more particularly in the range from 3:1 to 20:1, preferably in therange from 4:1 to 15:1 and more preferably in the range from 5:1 to10:1.
 6. The adsorptive structure according to any preceding claim,characterized in that the individual agglomerates are in self-supportingform.
 7. The adsorptive structure according to any preceding claim,characterized in that the individual agglomerates are in particle form,more particularly wherein the agglomerates have particle sizes,particularly particle diameters, in the range from 0.01 to 20 mm, moreparticularly in the range from 0.05 to 15 mm, preferably in the rangefrom 0.1 to 10 mm, more preferably in the range from 0.2 to 7.5 mm andeven more preferably in the range from 0.5 to 5 mm.
 8. The adsorptivestructure according to any preceding claim, characterized in that theindividual agglomerates each have a raspberry- or blackberrylikestructure.
 9. The adsorptive structure according to any preceding claim,characterized in that the organic polymer is in thermoplastic form,and/or in that the organic polymer is in heat-tacky form, and/or in thatthe organic polymer is selected from polymers from the group ofpolyesters, polyamides, polyethers, polyetheresters and/or polyurethanesand also their mixtures and copolymers.
 10. The adsorptive structureaccording to any preceding claim, characterized in that the organicpolymer is a preferably thermoplastic binder, more particularly apreferably thermoplastic hot-melt adhesive, preferably based on polymersfrom the group of polyesters, polyamides, polyethers, polyetheresters orpolyurethanes and also their mixtures and copolymers.
 11. The adsorptivestructure according to any preceding claim, characterized in that theorganic polymer, more particularly the binder, preferably the hot-meltadhesive, is solid at 25° C. and atmospheric pressure, and/or in thatthe organic polymer, more particularly the binder, preferably thehot-melt adhesive, has a melting or softening range above 100° C.,preferably above 110° C. and more particularly above 120° C., and/or inthat she organic polymer, more particularly the binder, preferably thehot-melt, adhesive, has a thermal stability temperature of at least 100°C., preferably at least 125° C. and more particularly at least 150° C.12. The adsorptive structure according to any preceding claim,characterized in that the adsorbent particles, of the individualagglomerates are covered and/or coated with organic polymer to at most50%, more particularly to at most 40%, preferably to at most 30% andmore preferably to at most 20% of their surface.
 13. The adsorptivestructure according to any preceding claim, characterized in that theadsorbent particles have a porous structure, and/or in that theadsorbent particles are in granular, more particularly spherical, form.14. The adsorptive structure according to any preceding claim,characterized in that the adsorbent particles have particle sizes, moreparticularly particle diameters, in the range from 0.001 to 3 mm, moreparticularly in the range from 0.005 to 2.5 mm, preferably in the rangefrom 0.01 to 2 mm, more preferably in the range from 0.02 to 1.5 mm andeven more preferably in the range from 0.05 to 1 mm.
 15. The adsorptivestructure according to any preceding claim, characterized in that theadsorbent particles have median particle sizes, more particularly medianparticle diameters (D50), in the range from 0.01 to 2 mm, moreparticularly in the range from 0.05 to 1.5 mm and preferably in therange from 0.1 to 1 mm.
 16. The adsorptive structure according to anypreceding claim, characterized in that the adsorbent particles consistof a material selected, from the group of activated carbon; zeolites;inorganic oxides, more particularly silicon dioxides, silica gels andaluminum oxides; molecular sieves; mineral granulates; klathrates;metal-organic framework materials (MOFs) and also their mixtures, morepreferably activated carbon, and/or in that the adsorbent particles areformed from granular, more particularly spherical, activated carbon. 17.The adsorptive structure according to any preceding claim, characterizedin that the adsorbent particles have a specific surface area (BETsurface area) of at least 500 m²/g, more particularly at least 750 m²/g,preferably at least 1000 m²/g and more preferably at least 1200 m²/g,and/or in that the adsorbent particles have a specific surface area (BETsurface area) in the range from 500 to 4000 m²/g more particularly inthe range from 750 to 3000 m²/g preferably in the range from 900 to 2500m²/g and more preferably in the range from 950 to 2000 m²/g.
 18. Theadsorptive structure according to any preceding claim, characterized inthat the adsorbent particles, more particularly the activated carbonparticles, preferably the activated carbon granules or activated carbonspherules, have a bursting pressure of at least 5 newtons, moreparticularly a bursting pressure in the range from 5 newtons to 50newtons, per particle.
 19. The adsorptive structure according to anypreceding claim, characterized in that the adsorbent particles have anadsorption volume V_(ads) of at least 250 cm³/g, more particularly atleast 300 cm³/g, preferably at least 350 cm³/g and more preferably atleast 400 cm³/g, and/or in that the adsorbent particles have anadsorption volume V_(ads), in the range from 250 to 3000 cm³/g, moreparticularly in the range from 300 to 2000 cm³/g and preferably in therange from 350 to 2500 cm³/g.
 20. The adsorptive structure according toany preceding claim, characterized in that the adsorbent particles havea Gurvich total pore volume of at least 0.50 cm³/g, more particularly atleast 0.55 cm³/g, preferably at least 0.60 cm³/g more preferably atleast 0.65 cm³/g and even more preferably at least 0.70 cm³/g, and/or inthat the adsorbent particles have a Gurvich total pore volume in therange from 0.50 to 2.0 cm³/g, more particularly in the range from 0.55to 1.5 cm³/g, preferably in the range from 0.60 to 1.2 cm³/g and morepreferably in the range from 0.65 to 1.0 cm³/g.
 21. The adsorptivestructure according to any preceding claim, characterized in that theadsorbent particles have a total porosity in the range from 10% to 80%,more particularly in the range from 20% to 75% and preferably in therange from 25% to 70%.
 22. The adsorptive structure according to anypreceding claim, characterized in that the adsorbent particles have aspecific total pore volume in the range from 0.01 to 4.0 cm³/g, moreparticularly in the range from 0.1 to 3.0 cm³/g, and preferably in therange from 0.2 to 2.0 cm³/g, more particularly wherein the proportion ofpores having pore diameters≦75 Å is at least 65%, more particularly atleast 70% and preferably at least 75%.
 23. The adsorptive structureaccording to any preceding claim, characterized in that the agglomeratesare processed into a molded part, more particularly via compressionmolding.
 24. The adsorptive structure according to any preceding claim,characterized in that the adsorptive structure, more particularly in theform of a loose bed or in the form of a molded part, has a length-basedpressure drop at a flow rate of 0.2 m/s of at most 200 Pa/cm, moreparticularly at most 150 Pa/cm, preferably at most 100 Pa/cm, morepreferably at most 90 Pa/cm, even more preferably at most 70 Pa/cm andyet even more preferably at most 50 Pa/cm and/or in that the adsorptivestructure in the form of a loose bed or in the form of a molded part hasa length-based pressure drop at a flow rate of 0.2 m/s in the range from5 to 200 Pa/cm, more particularly in the range from 5 to 150 Pa/cm,preferably in the range from 5 to 100 Pa/cm, more preferably in therange from 7.5 to 90 Pa/cm and even more preferably in the range from 10to 80 Pa/cm.
 25. A process for producing adsorptive structures based onagglomerates of adsorbent particles according to the preceding claims,characterized in that a) first granular, preferably spherical adsorbentparticles on the one hand and particles of preferably thermoplasticorganic polymer, more particularly binder, on the other are brought intocontact and mixed, b) then the resulting mixture is heated totemperatures above the melting or softening temperature of the organicpolymer, and c) finally the resulting product is cooled to temperaturesbelow the melting or softening temperature of the organic polymer. 26.The process according to claim 25, characterized in that step b)comprises maintaining the attained temperature for a defined period,more particularly for at least one minute, preferably at least 5minutes, preferably at least 10 minutes, and/or for a period in therange from 1 to 600 minutes, more particularly in the range from 5 to300 minutes and preferably in the range from 10 to 150 minutes.
 27. Theprocess according to claim 25 or 26, characterized in that during theperformance of step b), more particularly in the course of the heatingand/or maintaining operation, an energy inputment, preferably viamixing, takes place, more particularly wherein the energy inputment isused to control the resulting agglomerate size.
 28. The processaccording to any preceding claim, characterized in that the process isperformed in a heatable rotary tube, more particularly a rotary tubeoven, more particularly wherein the rotary speed of the rotary tube isused to control the energy inputment and thus the resulting agglomeratesize.
 29. The process according to any preceding claim, characterized inthat the agglomerates resulting in step c) are processed in a subsequentstep d) into a molded part, more particularly by compression molding,more particularly wherein the processing into molded parts is effectedby heating, preferably to temperatures below the melting or softeningtemperature of the organic polymer.
 30. The process according to anypreceding claim, characterized in that the thermoplastic organicpolymer, more particularly binder, is used in the form of particles,more particularly granular or spherical particles, preferably in theform of particles solid at room temperature and atmospheric pressure,more particularly wherein the organic polymer is used with particlesizes in the range from 100 to 2000 μm, more particularly in the rangefrom 150 to 1500 μm and preferably in the range from 200 to 1000 μm,and/or more particularly wherein the size ratio of organic polymerparticles to adsorbent particles is chosen at not less than 1:1, moreparticularly at not less than 1.25:1, preferably at not less than 1.5:1,more preferably at not less than 2:1 and even more preferably at notless than 3:1.
 31. The process according to any preceding claim,characterized in that the weight ratio of adsorbent particles to organicpolymer is at least 2:1, more particularly at least 3:1, preferably atleast 5:1, more preferably at least 7:1 and even more preferably atleast 8:1, and/or in that the weight ratio of adsorbent particles toorganic polymer varies in the range from 2:1 to 30:1, more particularlyin the range from 3:1 to 20:1, preferably in the range from 4:1 to 15:1and more preferably in the range from 5:1 to 10:1.
 32. The processaccording to any preceding claim, characterized in that the organicpolymer used is a preferably thermoplastic binder, more particularly apreferably thermoplastic hot-melt adhesive, preferably based on polymersfrom the group of polyesters, polyamides, polyethers, polyetherestersand/or polyurethanes and their mixtures and copolymers.
 33. The processaccording to any preceding claim, characterized by one or more of thefeatures of the characterizing part of claims 1 to
 24. 34. The use ofadsorptive structures based on agglomerates of adsorbent particlesaccording to the preceding claims for the adsorption of toxics, noxiantsand odors, more particularly from gas or air streams or alternativelyfrom liquids, more particularly water.
 35. The use of adsorptivestructures based on agglomerates of adsorbent particles according to thepreceding claims for cleaning or purifying gases, gas streams or gasmixtures, more particularly air, or liquids, more particularly water.36. The use of adsorptive structures based on agglomerates of adsorbentparticles according to the preceding claims for use in adsorptionfilters and/or in the manufacture of filters, more particularlyadsorption filters.
 37. The use of adsorptive structures based onagglomerates of adsorbent particles according to the preceding claims asa sorption store for gases, more particularly hydrogen.
 38. The use ofadsorptive structures based on agglomerates of adsorbent particlesaccording to the preceding claims in the manufacture of adsorptivemolded parts, more particularly by compression molding.
 39. The useaccording to any one of claims 34 to 38, characterized in that theadsorptive structures based on agglomerates of adsorbent particles areused in a loose bed.
 40. The use according to any one of claims 34 to38, characterized in that the adsorptive structures based onagglomerates of adsorbent particles are used in the form of a moldedpart manufacture therefrom via compression molding in particular.
 41. Afilter comprising adsorptive structures based on agglomerates ofadsorbent particles, more particularly as defined in the precedingclaims, preferably in the form of a loose bed, characterized in that thefilter has a length-based pressure drop at a flow rate of 0.2 m/s of atmost 200 Pa/cm and more particularly in the range from 5 to 200 Pa/cm.42. The filter according to claim 41, characterized in that the filterhas a length-based pressure drop at a flow rate of 0.2 m/s of at most150 Pa/cm, preferably at most 100 Pa/cm, more preferably at most 90Pa/cm, even more preferably at most 70 Pa/cm and yet even morepreferably at most 50 Pa/cm and/or in that the filter has a length-basedpressure drop at a flow rate of 0.2 m/s in the range from 5 to 150Pa/cm, preferably in the range from 5 to 100 Pa/cm, more preferably inthe range from 7.5 to 90 Pa/cm and even more preferably in the rangefrom 10 to 80 Pa/cm.
 43. An adsorptive molded part constructed from amultiplicity of adsorptive structures based on agglomerates of adsorbentparticles, more particularly as defined in claims 1 to
 24. 44. A processfor producing an adsorptive molded part according to claim 43,characterized in that adsorptive structures based on agglomerates ofadsorbent particles, more particularly as defined in claims 1 to 24, arecompression molded.
 45. A filter comprising an adsorptive molded partaccording to claim 43.